1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2018 FUJITSU LIMITED. All rights reserved.
4 * Author: Xiao Yang <yangx.jy@cn.fujitsu.com>
5 */
6 /*
7 * Description:
8 * If one memory is already locked by mlock2() with MLOCK_ONFAULT and then
9 * it is locked again by mlock()(or mlock2() without MLOCK_ONFAULT), the
10 * VmLck field in /proc/pid/status should increase once instead of twice.
11 *
12 * This issue has been fixed in kernel:
13 * 'b155b4fde5bd("mm: mlock: avoid increase mm->locked_vm on mlock() when already mlock2(,MLOCK_ONFAULT)")'
14 */
15 #include <errno.h>
16 #include <unistd.h>
17 #include <sys/mman.h>
18 #include <linux/mman.h>
19
20 #include "tst_test.h"
21 #include "lapi/syscalls.h"
22 #include "lapi/mlock2.h"
23
24 static unsigned long pgsz;
25 static char *addr;
26
verify_mlock2(void)27 static void verify_mlock2(void)
28 {
29 unsigned long bsize, asize1, asize2;
30
31 SAFE_FILE_LINES_SCANF("/proc/self/status", "VmLck: %lu", &bsize);
32
33 TEST(tst_syscall(__NR_mlock2, addr, pgsz, MLOCK_ONFAULT));
34 if (TST_RET != 0) {
35 if (TST_ERR == EINVAL) {
36 tst_res(TCONF,
37 "mlock2() didn't support MLOCK_ONFAULT");
38 } else {
39 tst_res(TFAIL | TTERRNO,
40 "mlock2(MLOCK_ONFAULT) failed");
41 }
42 return;
43 }
44
45 SAFE_FILE_LINES_SCANF("/proc/self/status", "VmLck: %lu", &asize1);
46
47 if ((asize1 - bsize) * 1024 != pgsz) {
48 tst_res(TFAIL,
49 "mlock2(MLOCK_ONFAULT) locked %lu size, expected %lu",
50 (asize1 - bsize) * 1024, pgsz);
51 goto end;
52 }
53
54 TEST(tst_syscall(__NR_mlock2, addr, pgsz, 0));
55 if (TST_RET != 0) {
56 tst_res(TFAIL | TTERRNO, "mlock2() failed");
57 goto end;
58 }
59
60 SAFE_FILE_LINES_SCANF("/proc/self/status", "VmLck: %lu", &asize2);
61
62 if (asize1 != asize2) {
63 tst_res(TFAIL, "Locking one memory again increased VmLck");
64 } else {
65 tst_res(TPASS,
66 "Locking one memory again didn't increased VmLck");
67 }
68
69 end:
70 SAFE_MUNLOCK(addr, pgsz);
71 }
72
setup(void)73 static void setup(void)
74 {
75 pgsz = getpagesize();
76 addr = SAFE_MMAP(NULL, pgsz, PROT_WRITE,
77 MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
78 }
79
cleanup(void)80 static void cleanup(void)
81 {
82 if (addr)
83 SAFE_MUNMAP(addr, pgsz);
84 }
85
86 static struct tst_test test = {
87 .test_all = verify_mlock2,
88 .setup = setup,
89 .cleanup = cleanup,
90 .needs_root = 1,
91 };
92